This disclosure is directed to systems and methods for incorporating a learning algorithm for adaptive feed forward control to assist in automatically rejecting repetitive torque disturbances for mechanically moving parts in image forming devices.
A variety of systems of methods are conventionally used to perform electrophotographic and/or xerographic image production and/or reproduction in image forming devices. One common system includes a transfer subsystem that further includes an electrophotographic photoreceptor belt.
FIGS. 1 and 2 illustrate a side elevation view and a front elevation view, respectively, of a schematic of a transfer subsystem 100, which includes a photoreceptor belt 110. A photoreceptor belt motor drive unit 122 engages the photoreceptor belt 110 and moves the photoreceptor belt 110 across a series of support rollers 124, 130, 132, 134, 142, 144, 146, and/or a plurality of non-rotating support bars 152, 154, 156, 158.
Typically, photoreceptor belts are fabricated from long sheets of photoreceptor material that are cut to size. The ends of the cut photoreceptor material are welded, or otherwise mated, together in order to form a continuous belt. This fabrication process produces a photoreceptor belt seam 115 at the point where the ends of the photoreceptor belt 110 are welded, or otherwise mated, together.
Some transfer subsystems, such as the one shown in FIGS. 1 and 2, include an acoustic transfer assist (ATA) module 120, which draws the photoreceptor belt 110 into a plenum using a vacuum. The ATA module 120 vibrates the photoreceptor belt 110 in the plenum to aid in transferring toner from the photoreceptor belt 110 to an image receiving medium.
In areas of the photoreceptor belt 110 where there is no seam, a tight vacuum is maintained in the ATA module 120. However, when the photoreceptor belt seam 115 of the photoreceptor belt 110 crosses the ATA module 120, the vacuum seal is momentarily broken. Drag of the photoreceptor belt 110 on the photoreceptor belt motor drive unit 122 momentarily reduces causing the photoreceptor belt motor drive unit 122 to speed up. Speed of the photoreceptor belt motor drive unit 122 must be tightly controlled for reasons that will be discussed in greater detail below. Photoreceptor belt velocity sensors (not shown) sense the increase in velocity of the photoreceptor belt motor drive unit 122. A motor control device reacts to readjust the speed of the photoreceptor belt motor drive unit 122 and the photoreceptor belt 110.
Even a momentary perturbation in photoreceptor belt velocity during imaging affects imaging results by, for example, producing defects in output hard-copy images transferred to an image receiving medium. Color photoreceptor belt-based systems include a plurality of imaging stations, each for a different one of a plurality of primary colors. An output multi-color spectral image is produced when toner particles of one or more of the primary colors are attracted to a respective one of a plurality of identical transfer images electrostatically formed in a plurality of discrete positions for each single primary color on the photoreceptor belt 110. As the photoreceptor belt 110 passes over the image receiving medium, toner is transferred one color at a time to the image receiving medium. Each of the primary colors of toner particles mix with any previously laid down on the image receiving medium in an image-on-image transfer process. A single pass of a plurality of transfer images, each laden with a single primary color on the photoreceptor belt, forms the mix of colors necessary to produce and/or reproduce the output color image on the image receiving medium.
Precise control of the velocity and the position of the photoreceptor belt 110 is necessary in order to attempt to ensure that each of the plurality of separate single color images is precisely overlaid on the image receiving medium in order to produce the output color image. When individual single color images do not correctly align, based mechanical transients and/or disturbances in the transfer subsystems such as, for example, velocity and/or position mismatches, or transient errors in control of the photoreceptor belt 110, image quality will decrease because the colors do not precisely line up. Such defects in output hard-copy images in electrophotographic and/or xerographic image forming devices are referred to alternatively as misregistration of colors or color-to-color registration errors. Such misregistration of colors may initially fall below any detectable threshold, but increases, i.e., becomes more pronounced and/or noticeable, as image-on-image systems and/or system components age or wear under use.